The background description provided herein is for the purpose of generally presenting the context of the disclosure. Work of the presently named inventors, to the extent it is described in this background section, as well as aspects of the description that may not otherwise qualify as prior art at the time of filing, are neither expressly nor impliedly admitted as prior art against the present disclosure.
Diesel engine operation involves combustion that generates exhaust gas. During combustion, an air/fuel mixture is delivered through an intake valve to cylinders and is combusted therein. After combustion, the piston forces the exhaust gas in the cylinders into an exhaust system. The exhaust gas may contain emissions such as oxides of nitrogen (NOx) and carbon monoxide (CO).
More and more exhaust hardware technology is being added to meet emissions on diesel applications. After treatment of exhaust gases includes the installation of multiple bricks, mixers and injectors for the exhaust stream. Because of the additional exhaust gas components, the flow is mixed in the exhaust conduits. Depending on the packaging, the after-treatment components allow the exhaust gases to swirl within the exhaust gas system. Sensors are typically placed in the exhaust gas system to provide feedback for various types of engine controls. Because of the swirling, differences in the readings for temperature sensors of a diesel particulate filter, for example, may not be accurate. Inaccurate readings of the temperature of the diesel particulate filter may lead to damage of the diesel particulate filter or not allow the diesel particulate filter to change the exhausted emission as designed.